diff options
| author | Tom Rondeau <trondeau@vt.edu> | 2013-03-15 20:49:05 -0400 |
|---|---|---|
| committer | Tom Rondeau <trondeau@vt.edu> | 2013-03-15 20:49:05 -0400 |
| commit | 3d38e82e7d87dfc01132b199e33b53add8a706fa (patch) | |
| tree | af4545bcf3cea24dc30571601116a3a89381ad5d /gr-atsc/src/python/all_atsc.py | |
| parent | 39ff6d4814c858f2dbaf3c8007940872c46d6c95 (diff) | |
atsc: adjustments to atsc to start to conform to v3.7 structure.
Not going to comply completely with the new structure; just wanted to get it so that it looked more consistent once installed.
Diffstat (limited to 'gr-atsc/src/python/all_atsc.py')
| -rw-r--r-- | gr-atsc/src/python/all_atsc.py | 142 |
1 files changed, 0 insertions, 142 deletions
diff --git a/gr-atsc/src/python/all_atsc.py b/gr-atsc/src/python/all_atsc.py deleted file mode 100644 index 7cac785149..0000000000 --- a/gr-atsc/src/python/all_atsc.py +++ /dev/null @@ -1,142 +0,0 @@ -#!/usr/bin/env /usr/bin/python -# -# Copyright 2004 Free Software Foundation, Inc. -# -# This file is part of GNU Radio -# -# GNU Radio is free software; you can redistribute it and/or modify -# it under the terms of the GNU General Public License as published by -# the Free Software Foundation; either version 2, or (at your option) -# any later version. -# -# GNU Radio is distributed in the hope that it will be useful, -# but WITHOUT ANY WARRANTY; without even the implied warranty of -# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -# GNU General Public License for more details. -# -# You should have received a copy of the GNU General Public License -# along with GNU Radio; see the file COPYING. If not, write to -# the Free Software Foundation, Inc., 59 Temple Place - Suite 330, -# Boston, MA 02111-1307, USA. -# -# This module starts the atsc processing chain taking the captured -# off-air signal created with: -# -# uhd_rx_cfile.py --samp-rate=6.4e6 -# -f <center of tv signal channel freq> -# -g <appropriate gain for best signal / noise> -# -s output shorts -# -# All this module does is multiply the sample rate by 3, from 6.4e6 to -# 19.2e6 complex samples / sec, then lowpass filter with a cutoff of 3.2MHz -# and a transition band width of .5MHz. Center of the tv channels is -# then at 0 with edges at -3.2MHz and 3.2MHz. - -from gnuradio import gr, atsc -from gnuradio import filter -from gnuradio import blocks -import sys, os, math - -def graph (args): - - nargs = len(args) - if nargs == 2: - infile = args[0] - outfile = args[1] - else: - raise ValueError('usage: interp.py input_file output_file\n') - - tb = gr.top_block () - - # Convert to a from shorts to a stream of complex numbers. - srcf = blocks.file_source (gr.sizeof_short,infile) - s2ss = blocks.stream_to_streams(gr.sizeof_short,2) - s2f1 = blocks.short_to_float() - s2f2 = blocks.short_to_float() - src0 = blocks.float_to_complex() - tb.connect(srcf, s2ss) - tb.connect((s2ss, 0), s2f1, (src0, 0)) - tb.connect((s2ss, 1), s2f2, (src0, 1)) - - # Low pass filter it and increase sample rate by a factor of 3. - lp_coeffs = filter.firdes.low_pass ( 3, 19.2e6, 3.2e6, .5e6, filter.firdes.WIN_HAMMING ) - lp = filter.interp_fir_filter_ccf ( 3, lp_coeffs ) - tb.connect(src0, lp) - - # Upconvert it. - duc_coeffs = filter.firdes.low_pass ( 1, 19.2e6, 9e6, 1e6, filter.firdes.WIN_HAMMING ) - duc = filter.freq_xlating_fir_filter_ccf ( 1, duc_coeffs, 5.75e6, 19.2e6 ) - # Discard the imaginary component. - c2f = blocks.complex_to_float() - tb.connect(lp, duc, c2f) - - # Frequency Phase Lock Loop - input_rate = 19.2e6 - IF_freq = 5.75e6 - # 1/2 as wide because we're designing lp filter - symbol_rate = atsc.ATSC_SYMBOL_RATE/2. - NTAPS = 279 - tt = filter.firdes.root_raised_cosine (1.0, input_rate, symbol_rate, .115, NTAPS) - # heterodyne the low pass coefficients up to the specified bandpass - # center frequency. Note that when we do this, the filter bandwidth - # is effectively twice the low pass (2.69 * 2 = 5.38) and hence - # matches the diagram in the ATSC spec. - arg = 2. * math.pi * IF_freq / input_rate - t=[] - for i in range(len(tt)): - t += [tt[i] * 2. * math.cos(arg * i)] - rrc = filter.fir_filter_fff(1, t) - - fpll = atsc.fpll() - - pilot_freq = IF_freq - 3e6 + 0.31e6 - lower_edge = 6e6 - 0.31e6 - upper_edge = IF_freq - 3e6 + pilot_freq - transition_width = upper_edge - lower_edge - lp_coeffs = filter.firdes.low_pass(1.0, - input_rate, - (lower_edge + upper_edge) * 0.5, - transition_width, - filter.firdes.WIN_HAMMING); - - lp_filter = filter.fir_filter_fff(1,lp_coeffs) - - alpha = 1e-5 - iir = filter.single_pole_iir_filter_ff(alpha) - remove_dc = blocks.sub_ff() - - tb.connect(c2f, fpll, lp_filter) - tb.connect(lp_filter, iir) - tb.connect(lp_filter, (remove_dc,0)) - tb.connect(iir, (remove_dc,1)) - - # Bit Timing Loop, Field Sync Checker and Equalizer - - btl = atsc.bit_timing_loop() - fsc = atsc.fs_checker() - eq = atsc.equalizer() - fsd = atsc.field_sync_demux() - - tb.connect(remove_dc, btl) - tb.connect((btl, 0),(fsc, 0),(eq, 0),(fsd, 0)) - tb.connect((btl, 1),(fsc, 1),(eq, 1),(fsd, 1)) - - # Viterbi - - viterbi = atsc.viterbi_decoder() - deinter = atsc.deinterleaver() - rs_dec = atsc.rs_decoder() - derand = atsc.derandomizer() - depad = atsc.depad() - dst = blocks.file_sink(gr.sizeof_char, outfile) - tb.connect(fsd, viterbi, deinter, rs_dec, derand, depad, dst) - - dst2 = blocks.file_sink(gr.sizeof_gr_complex, "atsc_complex.data") - tb.connect(src0, dst2) - - tb.run () - -if __name__ == '__main__': - graph (sys.argv[1:]) - - |